Field of the Invention
The present invention relates to a resin composition. Specifically, the present invention relates to a resin composition comprising a resin with a vinyl-containing or allyl-containing group, bismaleimide, and a cross-linking agent, and a prepreg and laminate prepared using the same.
Descriptions of the Related Art
Printed circuit boards (PCBs) are circuit substrates that are used for electronic devices to load other electronic components and to electrically connect the components to provide a stable circuit working environment. One kind of conventional printed circuit board is a copper clad laminate (CCL), which is primarily composed of resin(s), reinforcing material(s) and copper foil(s). Conventional resins include epoxy resins, novolac resins, polyamine formaldehyde resins, silicone resins or polytetrafluoroethylene resins; and conventional reinforcing materials include glass fiber cloths, glass fiber mats, insulating papers or linen cloths.
In general, a printed circuit board can be prepared using the following method: immersing a reinforcing material, such as glass fiber fabric into a resin (such as epoxy resin), and curing the immersed glass fiber fabric into a half-hardened state, i.e. B-stage, to obtain a prepreg; superimposing certain layers of the prepregs and superimposing a metal foil on at least one external surface of the superimposed prepregs to provide a superimposed object; hot-pressing the superimposed object, i.e. C-stage, to obtain a metal clad laminate; etching the metal foil on the surface of the metal clad laminate to form a defined circuit pattern; and finally, drilling a plurality of holes on the metal clad laminate and plating these holes with a conductive material to accomplish the preparation of the printed circuit board.
Printed circuit boards prepared by using an epoxy resin may be provided with proper physicochemical properties such as heat resistance, chemical stability, mechanical strength, etc. However, printed circuit boards thus prepared are also provided with a high dielectric constant (Dk) value, a high dissipation factor (Df) value, and high H2O absorption rate, which all lead to the deterioration of the signal transmission quality (e.g., a slow signal transmission rate and signal loss). As a result, the laminates prepared by using an epoxy resin gradually fail to meet the requirements for high frequency and high-speed signal transmission for smaller, lighter, and thinner electronic products. Hence, TW Patent No. 574313 provides a resin composition for producing laminates, which lowers the Dk and Df values of the printed circuit boards by adding polyphenylene ether resin and bismaleimide into epoxy resin. However, in practical application, due to the difference in the polarity of chemical structure, polyphenylene ether resin and epoxy resin are poorly compatible with each other, making it difficult to process and limiting the usage of the resin composition. It is also hard to sufficiently utilize the properties of polyphenylene ether resin in the composition.
U.S. Pat. No. 5,218,030 disclosed a resin composition using polyphenylene ether resin and triallyl isocyanurate (TAIC). Although the resin composition can avoid the disadvantages of using epoxy resins, the material, thus prepared, lacks a sufficient heat resistance property. U.S. Pat. No. 8,034,442 B2 disclosed a resin composition, which comprises diphenylmethane bismaleimide, alkenyl phenol ether compounds, alkenyl aromatic comonomer, and TAIC. The resin composition is capable of providing a complex material with excellent heat resistance. However, since the ingredients of the resin composition are expensive, the resin composition is mainly used to produce a high level laminate requiring extremely high heat resistance but not suitable to mass-produce middle or low level laminates (such as FR-4 laminates).
In this regard, the present invention provides a resin composition for preparing a laminate, wherein the gel time of the resin composition is short, which can considerably shorten the processing time. The laminate prepared thereby is provided with outstanding physicochemical properties, adhesion to a metal foil, and electrical properties.